The field of the invention includes a collapsible walker with a release mechanism for use by the aged or infirmed.
Many of the aged or infirmed have difficulty walking because they have weakness of the extremities. In order to help these people remain independently mobile, various walking devices have been developed that aid the user in supporting his or her weight. The open walking frame or walker is such a device. Walkers generally consist of four legs attached to form a square frame with at least one side open so that the user can stand within the four legs. The frame has handles so the user can pick up the walker, set it in front, and lean on it to walk forward. In this way, the user can support some of his or her weight with the arms and shoulders. Further, the user can balance his or her weight more easily by shifting to the different sides of the walker.
Walkers have been developed that fold to a small space so that they can be more easily stored when not in use. These types of walkers are comprised of three frames, one in the front and one on each side, with the user stepping into the walker from the rear. When the walker is not being used, the side frames can each be rotated onto the front frame of the walker to reduce storage space. The side frames are locked in the open position by various mechanisms.
There are significant problems for patients with dexterity problems with walkers as presently constructed that have not been adequately addressed by the art. One problem relates to the use of spring-loaded push buttons as locking devices, which require substantial pressure to manipulate, and require the patient to remove his or her hands from the walker handles, thereby removing support when it is most needed. For example, Leonard U.S. Pat. No. 5,862,825 uses an action that requires levers to be pushed downwardly to effect the release of a locking mechanism in which a pivot pin and barrel arrangement is mounted inboard of the side frames. Spies et al U.S. Pat. No. 5,529,425 requires actuating handles to be depressed to release the side frames for folding, and may be operated in only a single direction. Della-Porta U.S. Pat. No. 2,842,387 and Hillstrom et al U.S. Pat. No. 6,032,908 use tubes that rotate within sleeves but do not provide specific locking points. Additionally, the Hillstrom et al cam assembly is only actuated by moving control handles up and down. Battiston, Sr. et al U.S. Pat. No. 4,518,002 requires the depression of plungers to release side frames from the front frame of a walker.
Another problem is that current walker styles are not user friendly. When using a walker to stand, a patient often needs more than one locked position to have more room to maneuver than provided by the typical walker in its locked open position. For example, Battiston, Sr. et al, cited above, allows only one locking position.
The walker of the present invention overcomes the foregoing deficiencies. It is easy to use by patients with dexterity problems in that it enables a patient to open and close the walker without taking his or her hands off the walker. This is accomplished by a paddle shaped lever arranged to interact with locking pins by lateral movement in either direction.
In one embodiment of the invention, the walker has a single locking position for each of the side frames. In another embodiment, the walker has at least two locking positions for each of the side frames wherein the walker can be hyper-extended, spreading out and locking the walker to a more fully opened configuration, allowing the walker to be pulled closer to the patient making it easier for the patient to lift himself or herself up to a standing position.
In a specific embodiment, a foldable walker is provided comprising front legs defining a front frame, and rear legs and upper members defining side frames with the front legs. The side frames are pivotally connected to the front frame for rotation relative to the front frame. Locking mechanisms are provided at respective pivotal connections, each locking mechanism comprising a housing containing a locking pin pivotally connected to the lever to be movable by the lever. The lever is also pivotally connected, to the housing adjacent an end of the locking pin. The front legs are each formed with at least one aperture to receive the distal end of the locking pin. The aperture is located at a radial angle with respect to the front frame so as to define an open position of the walker and to lock the side frames to the front frame in the open position. The locking pin can have a plate adjacent its distal end and a spring bearing on the plate to spring load the locking pin to its locking position. Paddle shaped levers connect to respective locking mechanisms and are arranged so that lateral movement of the levers in either direction withdraws the locking pin from the respective aperture. This releases the side frames to allow the walker to fold by rotation of the side frames to close with the front frame.
The front legs of the walker can be formed with tubular hinge tubes to which the locking mechanisms are rotatably connected. The connection can be made to rotation rings carried by the hinge tubes via bearing rings fixed to the hinge tubes. One or more rigid support members can bridge and interconnect the hinge tubes.
In a further embodiment of the invention, each locking mechanism can lock to one of two or more positions wider than the open position. In this embodiment, the front legs are each formed with a pair of radially spaced apertures formed to receive the distal end of the locking pin. A first of the apertures is located at a first radial angle with respect to the front frame whereby to define the open position of the walker. The second of the apertures is located at a second radial angle with respect to the front frame, an angle that is greater than the first radial angle to define an extended open position of the walker, which can be referred to as a hyper-extended position.